Scanning probe microscopes are used to detect a physical quantity generated through the interaction between a probe and the surface of a sample when the sample and the probe that is arranged so as to face the sample are made to come close to each other so that the probe or the sample is scanned in order to measure the form of the surface of the sample with the resolution at an atomic level. Scanning tunneling microscopes (STMs) and atomic force microscopes (AFMs) fall within such scanning probe microscopes.
Atomic force microscopes (AFMs) are used to measure a microscopic interatomic force generated between atoms at the tip of a probe and atoms on the surface of a sample when the probe supported by a cantilever or the like is made to come close to the surface of the sample in order to measure the uneven form on the surface of the sample from the track of the probe or the sample in the direction of the height when the distance between the probe and the sample is adjusted so that the interatomic force between them becomes constant while scanning the surface of the sample by using the properties such that the interatomic force is uniquely determined by the distance between the probe and the sample.
In addition, scanning tunneling microscopes (STMs) are used to observe the form on the surface of a sample with the resolution at an atomic level by applying a voltage between the sample and a probe that is provided so as to face this sample and scanning the probe or the sample so that the tunneling current that flows between the two becomes constant. That is to say, the unevenness on the surface of a sample is measured by measuring the amount of control by a precision drive mechanism such as of a piezoelectric element with which the height of the probe or the sample is controlled so that the tunneling current becomes constant by using such properties that the tunneling current is uniquely determined by the distance between the probe and the sample.
FIG. 7 is a schematic diagram showing a general configuration of an atomic force microscope (AFM). Here, one direction that is horizontal relative to the ground is the X direction (left and right directions), the direction that is horizontal relative to the ground and perpendicular to the X direction is the Y direction (front and rear directions), and the direction that is perpendicular to the X and Y directions is the Z direction (upward and downward directions).
In addition, FIG. 8 is a plan diagram showing a general cantilever holder 20. FIGS. 9A and 9B are cross-sectional diagrams along line C-C in FIG. 8. FIG. 9A is a diagram showing the completion of the attachment of a cantilever 1 to the cantilever holder 20. FIG. 9B is a diagram showing the process during the attachment of the cantilever 1 to the cantilever holder 20.
The atomic force microscope (AFM) is provided with the cantilever holder 20 for supporting the cantilever 1, displacement measuring unit portions 3, 4, 5 and 6 for measuring the displacement of the cantilever 1, a table 8 in disc form on which a sample S is to be placed, a piezo scanner (scanning means) 7 of which the upper surface has the table 8 attached thereto, and a control unit (not shown).
Various types of measurement modes such as a contact mode, a contact height mode, a non-contact mode and a dynamic mode are stored in the control unit.
The “contact mode” is a mode for measuring the height from the amount of feedback by scanning the surface of the sample S while the control unit carries out feedback control so that the repulsive force working between the cantilever 1 and the sample S becomes constant. In addition, the “contact height mode” is a mode for measuring the height of the surface of the sample S from the amount of deflection of the cantilever 1 by scanning the surface of the sample S while maintaining the height of the cantilever 1 at a constant. Furthermore, the “non-contact mode” is a mode for measuring the height of the surface of the sample S from the amount of feedback by scanning the surface of the sample S while carrying out feedback control so that the attractive force working between the cantilever 1 that oscillates in the vicinity of the resonance point and the sample S becomes constant. Moreover, the “dynamic mode” is a mode for measuring the height of the surface of the sample S from the amount of feedback by scanning the surface of the sample S while carrying out feedback control so that the repulsive force working between the cantilever 1 that oscillates in the vicinity of the resonance point and the sample S becomes constant.
The cantilever 1 is in a plate form having a length of 100 μm and a thickness of 0.8 μm, for example, and an acute probe 1a is formed on the surface of one tip portion. In addition, the other tip portion of the cantilever 1 can be attached to a predetermined point on the cantilever holder 20.
The displacement measuring unit portions 3 through 6 are a laser beam source 3 for emitting a laser beam, a beam splitter 4 for directing the incoming laser beam toward the rear of the cantilever 1, a mirror 5 for adjusting the direction of the laser beam that has been reflected from the rear of the cantilever 1, and a photodiode 6 for detecting the reflected laser beam. As a result, the form of the surface of the sample S is detected by using the fact that the direction of reflection of the beam reflected from the rear of the cantilever 1 changes depending on the deflection (displacement) of the cantilever 1 in the above-described various types of measurement modes.
The table 8 is in a disc form having a diameter of 15 mm as viewed from the top and a thickness of 4 mm as viewed from the side, for example.
The table 8 is attached to and integrated with the upper surface of the piezo scanner 7 so that the table 8 can be scanned in the X direction, in the Y direction and in the Z direction using a piezo element. That is to say, the sample S placed on the table 8 can be scanned in the X, Y and Z directions by the control unit.
Incidentally, the operator selects one cantilever 1 from among a number of types of cantilevers 1 contained in a cantilever case for use in accordance with the sample S and the purpose of measurement before the unevenness on the surface of the sample S is measured with the atomic force microscope. That is to say, it is necessary for the operator to attach the other tip portion of the selected cantilever 1 to a predetermined point (below-described attachment portion 21) on the cantilever holder 20.
The cantilever holder 20 is provided with a main body portion 22 having the attachment portion 21 to which the cantilever 1 is to be attached and a grip 23 held by the operator when the cantilever holder 20 is attached to the atomic force microscope.
The main body portion 22 is in a U shape having a left side main body portion 22a, a right side main body portion 22b and a rear side main body portion 22c for connecting the rear of the left side main body portion 22a and the rear of the right side main body portion 22b in the X direction, where the attachment portion 21 is formed in the center on the upper surface of the left side main body portion 22a. 
The attachment portion 21 has an attachment platform 21a in a rectangular parallelepiped form (2 mm×4 mm×3 mm, for example), a plate spring (pressing member) 21b in a Y shape and a lifting member (lifting mechanism) 21c in a columnar form arranged in the Z direction (see Patent Document 1).
Here, the upper surface of the attachment platform 21a is an inclined surface that gradually declines in the −X direction at an angle of 7°, for example.
The right side portion of the plate spring 21b is in a U shape having a rear plate body, a front plate body and a left plate body for connecting the left portion of the rear plate body and the left portion of the front plate body in the Y direction. The distance between the front plate body and the rear plate body is 3 mm, for example, and one wire 21e (having a diameter of 0.3 mm and a length of 5 mm, for example) is provided between the right portion of the rear plate body and the right portion of the front plate body so as to connect the two in the Y direction. Meanwhile, the left side portion of the plate spring 21b is fixed to the upper surface of the left side main body portion 22a via a screw 21d so that the right side portion of the plate spring 21b can move upward (Z direction) when the plate spring 21b bends with the left end portion of the plate spring 21b being the axis. Thus, the wire 21e in the right end portion of the plate spring 21b is provided so as to be pressed against the upper surface of the attachment platform 21a by means of the elastic force of the plate spring 21b. 
In addition, a through hole 22d in a columnar form is created in the location of the left side main body portion 22a beneath the center portion of the plate spring 21b, and a lifting member 21c in a columnar form is provided within the through hole 22d that is in the Z direction. The height of the lifting member 21c is greater than the height of the through hole 22d so that the upper end portion of the lifting member 21c protrudes from the upper surface of the left side main body portion 22a so as to press the middle portion of the plate spring 21b upward (Z direction). That is to say, a gap for arranging the cantilever 1 is created between the upper surface of the attachment platform 21a and the lower surface of the wire 21e when the middle portion of the plate spring 21b is pressed upward (Z direction). When the upper end portion of the lifting member 21c does not protrude from the upper surface of the left side main body portion 22a, the lower end portion of the lifting member 21c protrudes from the lower surface of the left side main body portion 22a. 
Next, the attachment method for attaching the cantilever 1 to the cantilever holder 20 is described. First, the operator selects an optimal type of cantilever 1 in accordance with the size of the sample S, and then places the cantilever holder 20 on the table so that the upper surface of the cantilever holder 20 faces upward. At this time, the lower end portion of the lifting member 21c protrudes from the lower surface of the left side main body portion 22a, and therefore, such a state is achieved that the upper surface of the cantilever holder 20 inclines relative to the horizontal surface (surface of the table). Next, the upper surface of the front portion and the upper surface of the rear portion of the left side main body portion 22a of the cantilever holder 20 are pressed downward with the left hand fingers. As a result, the upper surface of the cantilever holder 20 becomes parallel to the horizontal surface, and the lower end portion of the lifting member 21c is pressed upward with the surface of the table. As the lifting member 21c protrudes from the upper surface of the left side main body portion 22a, the right end portion of the plate spring 21b moves upward. That is to say, a gap is created between the upper surface of the attachment platform 21a and the lower surface of the wire 21e (see FIG. 9B).
In this state, tweezers (not shown) are held by the right hand, and the selected cantilever 1 is held by the tweezers. Then, the cantilever 1 held by the tweezers is inserted into the gap between the upper surface of the attachment platform 21a and the lower surface of the wire 21e, and thus is arranged. At this time, the cantilever 1 is positioned so that there is no shift in the location and at the angle.
Finally, pressing the upper surface of the front portion and the upper surface of the rear portion of the left side main body portion 22a of the cantilever holder 20 downward with the left hand fingers is gradually stopped in the state where the cantilever 1 is positioned, and thus, the cantilever 1 is sandwiched and fixed between the upper surface of the attachment platform 21a and the lower surface of the wire 21e (see FIG. 9A).